The present invention generally relates to handheld devices for dispensing lubrication and, in particular, an improved handheld gun having a display indicating one or more parameters of the gun and its operation, including an indication of the volume of lubricant dispensed by the gun.
Handheld powered lubricators, commonly referred to as “grease guns,” have widespread use for servicing bearings and other components of vehicles, farming equipment, and industrial machines. A grease gun typically includes a pump having a reciprocal plunger, a reservoir of grease, a discharge hose, and an electric motor which drives the pump. The motor is powered through an electrical cord or, for a cordless grease gun, by a battery. The grease gun discharges lubricant generally at a uniform pressure and volumetric output rate. A grease gun of this type is shown in United States Patent Application 20060108180, which is hereby incorporated by reference in its entirety.
Periodically, there is a need to dispense a particular amount of lubricant from a grease gun to a grease fitting. One drawback is that grease guns can be operated inefficiently and an operator is unsure of the quantity of lubricant dispensed. Because there is no visual indication of the number of pump cycles (i.e., reciprocations of the plunger), the operator must estimate whether a correct quantity of grease has been dispensed to a fitting. Often, the operator misjudges and a bearing is either under or over-lubricated, which is detrimental to operation and durability. The grease gun is also prone to damage should the motor overheat, such as due to a clogged fitting or an over-pressure condition inside the pump.
There is also a need to know how much lubricant is available in a reservoir of a grease gun so that the operator does not run out of lubricant.